Association Between Connectivity of Hippocampal Sub-Regions and Auditory Verbal Hallucinations in Schizophrenia

Abstract

Background: Hippocampal dysconnectivity has been detected in schizophrenia patients with auditory verbal hallucinations (AVHs). Neuroanatomical evidence has indicated distinct sub-regions in the hippocampus, but which sub-regions within the hippocampus may emerge dysfunction in the brain network, and the relationship between connection strength and the severity of this debilitating disorder have yet to be revealed. Masked independent component analysis (mICA), i.e., ICA restricted to a defined region of interest, can provide insight into observing local functional connectivity in a particular brain region. We aim to map out the sub-regions in the hippocampus with dysconnectivity linked to AVHs in schizophrenia. Methods: In this functional magnetic resonance imaging study of schizophrenia patients with ( n = 57) and without ( n = 83) AVHs, and 71 healthy controls, we first examined hippocampal connectivity using mICA, and then the correlation between connection metric and clinical severity was generated. Results: As compared with patients without AVHs, mICA showed a group of hyper-connections for the left middle part, as well as another group of hypo-connections for the bilateral antero-lateral and right antero-medial parts in patients with AVHs. Connectivity was linked to the clinical symptoms scores in the sample of patients with AVHs. Conclusion: These findings demonstrate that the left middle part is more densely connected, but the bilateral antero-lateral and right antero-medial parts are more sparsely connected in schizophrenia patients with AVHs. The findings in the present study show proof of precious location in the hippocampus mediating the neural mechanism behind AVHs in schizophrenia.

The Association Between Lentiform Nucleus Function and Cognitive Impairments in Schizophrenia

“…A T1-weighted anatomical imaging (TR = 8.2 ms, TE = 3.2 ms, slice thickness = 1.0 mm, field of view [FOV] = 256 mm × 256 mm, matrix = 256 × 256, and flip angle = 12°) and resting-state functional MRI (TR = 2,000 ms, TE = 30 ms, slice thickness = 3.5 mm, FOV = 240 mm × 240 mm, matrix = 64 × 64, and flip angle = 90°) were performed. Further details about image acquisition are detailed in previous articles ( Cui et al, 2019b ; Liu et al, 2019 ). Participants were instructed to relax with their eyes closed but keep from falling asleep during their MRI scan.…”

Cortical abnormalities and identification for first-episode schizophrenia via high-resolution magnetic resonance imaging

“…The high-resolution, T1-weighted, three-dimensional (3D) anatomical data were performed in the Department of Radiology by using a 3.0-T Magnetom Trio Tim imaging unit with an eight-channel phased-array head coil (Siemens, Erlangen, Germany) and protocols published previously (Chang et al, 2017; Chang et al, 2015; Cui et al, 2016; Cui, Liu, et al, 2017; Cui, et al, 2018; B. Li et al, 2017; L. Liu et al, 2019). Imaging was acquired by using a magnetization-prepared rapid gradient-echo sequence with the following parameters: repetition time (TR) = 2530 ms, echo time (TE) = 3.5 ms, flip angle = 7°, field of view = 256 mm × 256 mm, data matrix = 256 × 256, section thickness = 1 mm, section gap = 0 mm, number of sections = 192, and image resolution = 1 × 1 × 1 mm.…”

“…The high-resolution, T1-weighted, three-dimensional (3D) anatomical data were performed in the Department of Radiology by using a 3.0-T Magnetom Trio Tim imaging unit with an eight-channel phased-array head coil (Siemens, Erlangen, Germany) and protocols published previously (Chang et al, 2017;Chang et al, 2015;Cui et al, 2016;Cui, Liu, et al, 2017;Cui, et al, 2018;B. Li et al, 2017;L. Liu et al, 2019).…”

Altered Effective Connectivity in Schizophrenic Patients With Auditory Verbal Hallucinations: A Resting-State fMRI Study With Granger Causality Analysis

“…In previous models including the "memory intrusion", "selfmonitoring", "two hit bottom-up and top-down", and hybrid models, language, auditory, and memory brain networks were closely associated with AVH in patients with schizophrenia (4). The superior temporal gyrus (STG) (auditory cortex), Broca's area (speech production), Wernicke's area (language comprehension), hippocampus (memory retrieval), and putamen (initiating language representations) are the key areas responsible for AVH in schizophrenia, and showed functional alterations in previous brain imaging studies (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). Although aberrant FC associated with AVH has been reported in these regions in many resting-state fMRI studies (6,7,15,16,(19)(20)(21)(22)(23)(24)(25), the interactions between these regions have not been described completely.…”